Dangerous Decibels

Unit Summary

Students investigate sound in their environment, particularly how sounds impact their lives. At the beginning of the unit, students use online simulations to investigate the properties of sound and learn about the components of a sound wave. They identify the different sounds in their environment and place them into categories for analysis. Students complete a project where they develop a research question, collect data in the field about different sounds, and analyze their data. They use what they have learned to create a digital product that makes recommendations about teens and sound. At the end of the unit, students share their products and take an exam over the science content.

Curriculum-Framing Questions

Essential Question
How am I affected by the world around me?

Unit Questions
When are sounds too loud?
What meaning can I make from raw data?
How can I persuade others?

Content Questions
What is amplitude?
How are waves created?
How do different kinds of waves travel?

Assessment Processes

View how a variety of student-centered assessments are used in the Dangerous Decibels Unit Plan. These assessments help students and teachers set goals; monitor student progress; provide feedback; assess thinking, processes, performances, and products; and reflect on learning throughout the learning cycle.

Instructional Procedures

Unit Preparation

Create a Dangerous Decibels wiki for use throughout the unit.

Arrange for use of decibel reader probes and microphone probes. (See Internet Resources for sources.)

Unit Introduction

Conduct a discussion of the Essential Question, How am I affected by the world around me? Use the following discussion prompts as needed:

What features of your environment affect you?

How are your senses affected by your environment?

How, why, and when do you control the impact of your environment on your life?

What role does sound play in your environment?

What impact does sound have on your life?

Why should we be concerned about too much noise, or noise pollution?

Ask students to review sound waves by completing the Brainstorm-Share-Journal Graphic Organizer. Direct students to:

Fold and tear a piece of notebook paper into four sections, labeled Brainstorm, Changes, Questions, and Journal.

Work independently to brainstorm what they know about sound waves. (Give adequate time, and stop all students at the same point.)

Find a partner (or assign one) and exchange information from their brainstorm.

Add to the “Changes” section with anything they would like to add or alter from their original thinking in the brainstorm section.

Allow students to meet with at least one or two other classmates to discuss their thoughts about waves and sounds in the environment.

Phase 1: Sounds in Our Environment

Prepare students for the following activity by conducting a short discussion about the sounds in the school environment:

What are some of the sounds you would hear around the school?

How loud are these sounds?

What impact might the loudness of some sounds have on students?

What factors would effect the volume of the sounds?

Ask students to keep a record the types of sounds they hear throughout the day, using the Environmental Sounds Record.Conduct a quick mini-trial of the process by modeling an example with sounds in the classroom. Discuss some standard ways to describe sounds—loud/soft volume, short/long, high/low pitch, etc.

When students return with the completed records, ask the class to brainstorm some categories they could use to organize the sounds. Model how they can define attributes of the different sounds to create new categories.

Place students in groups of 3 to 5, and ask them to cut individual sound descriptions apart the forms so the sounds can be categorized in different ways. Encourage them to be creative in the categories they experiment with but to settle on some categories that they think would be useful for describing the impact of the sounds. Use the Categorizing Observational Checklist to assess students’ skills while they work.

After students categorize their sounds and share their categories with the class, ask the Unit Question, When are sounds too loud?

Ask students to respond in their journals to the prompt, What are some ways to judge whether a sound is too loud or too soft?

Phase 2: All about Sound

Use online simulations and animations to review basic concepts about sound. You may choose to include the following topics and simulations, based on the level of your students:

Wave Interference
View how a second set of sound waves creates an interference pattern

Wave on a String
Adjust the sound frequency and amplitude of an oscillator while viewing the wave pattern effects

Review key vocabulary related to sound and sound wave patterns. Discuss the relationship between volume and pitch of sounds with amplitude and frequency of sound waves. You may wish to use the interactive sites Components of Sound* and Listening to Waves* to demonstrate some of these concepts.

Show a chart similar to the following to the class and ask students to vote on how dangerous each type of sound is to a person’s hearing. If you wish, you could ask students to rank the sounds using Intel's Visual Ranking Tool. Students should discuss and explain their reasoning behind their ranking, particularly on what would make a sound sometimes dangerous and sometimes not dangerous.

Not dangerous at all

Maybe dangerous

Definitely dangerous

Sounds

1

2

3

Conversation with a friend

An exciting moment at a football game

A jet taking off

A baby crying

iPod or MP3 player

Getting yelled at by an adult

Using a snow blower

Fireworks

Television

Car stereo

Demonstrate the use of probes to practice measuring sounds, and give students the opportunity to measure different sounds around the school. If available, use mobile device apps that measure sound or digital probe attachments for mobile devices. When students return to the classroom, have them place their sound measurements on a continuum, from completely safe to very dangerous.

Phase 3: Dangerous Decibels Project

Place students in heterogeneous groups of 3 to 5 for the project.

Ask groups to do some Internet research on the effects of different kinds of environmental sounds, or break up Noise-Induced Hearing Loss www.nidcd.nih.gov/health/hearing/noise.asp* into sections for a jigsaw activity.

Conduct a whole class discussion during which groups share their research findings and discuss the impact of different kinds of noise on hearing. Encourage students to think about long term impact of noise pollution and how it might affect their lives.

Explain the project: Your group will create a digital product—a wiki, blog, electronic newsletter or brochure, video, or podcast—with information and recommendations about preventing hearing loss from noise. Introduce the Project Rubric.